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Homework Help: Check my static problem

  1. Nov 29, 2008 #1
    plz Check my static problem

    1. The problem statement, all variables and given/known data

    a roof that has a rise of 5 meteres for every 14 meters of horizontal run. A girl stands on a scale on the roof and the scale reads 120N . what is the actual weight of the girl? what force tends to slide the girl off of the roof?

    2. Relevant equations

    tan theta=opp/adj
    cos theta=adj/hyp

    3. The attempt at a solution
    i found the degree first, which is 19.65 degrees, I found this by using tan equation. Then I used this degree to find the weight of the grl, which is 127.39N, used cos equation. Then finally, using the degree again and tan equation, the force sliding the girl off the roof is 42.84N. I just want to know if I have the answer right? Thank you for the help!!!
  2. jcsd
  3. Nov 29, 2008 #2


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    Re: plz Check my static problem

    Pretty close. The girl's weight is correct. Also, there is a 42.8N force trying to slide her down the roof. What is the nature of that force? It may not be successful in making her slide if there is enough ________ available to offset this force.
  4. Nov 29, 2008 #3
    Re: plz Check my static problem

    are you talking about gravity??
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